The present invention relates to solid state ignition systems and more particularly to an inductive ignition system providing a multiple of sparks for each power stroke, over the entire speed range of an associated engine.
The advantage of solid state capacitor discharge and inductive ignition systems are known. Both systems, however, require additional mechanical devices to obtain the spark advance desired for efficient operation of the engine throughout the various speed and load conditions. In addition, inductive systems currently in use, require that current flow to the primary of the ignition coil be re-established as rapidly as possible after sparking throughout the speed range, in order to insure that adequate magnetic flux is present in the coil core, particularly at high speeds, for the subsequent spark.
In the present invention, novel circuitry is provided in which the primary current flow is not re-established until just before the next series of sparks occur, with consequent saving of electrical energy, particularly at the lower speeds.
In addition, the present invention provides a first spark plus an additional series of subsequent sparks in rapid succession, during a pre-selected time interval, for each power stroke. This series of rapid sparks insures that combustion of the cylinder mixture will occur, even with poor mixtures which may exist under cold, hot, flooded or idle conditions. The cylinder mixture, which is in a continuous state of turbulance, and not homogenuous prior to ignition, will be ignited by a succeeding spark, should the initial spark occur at the instant when a non-combustible mixture is in the vicinity of the spark plug gap.
The present invention also provides for obtaining the desired spark advance under speed and load variations, electronically.
With the circuitry of the present invention, the relatively large current supplied to the ignition coil, is fed directy from the battery, and only the relatively much lower control current is carried thru the ignition switch.
In the present invention, the overall inductance of the ignition coil has been reduced to a minimum in order to obtain the maximum energy storage in the magnetic core of the coil in the shortest possible time by; (1) a relatively low number of primary turns of large wire, (2 ) a ferrite core material having high flux storage capability, together with a minimum of residual flux when the magnetizing force is removed.